1. Field of the Invention
This invention relates to devices used to clip or cut hair, fur and the like of humans and animals. The new device provides for a disposable cutting head including blades to simplify in an economical maintenance of a relatively sharp cutting instrument.
2. Description of Related Art
There are currently in use a variety of devices for clipping, cutting and shearing hair and fur. These include devices commonly known as hair clippers or just clippers which in most instances modernly are powered by electric motors. Clippers as originally conceived and developed include cutting blades which are intended to be removed from the head of a clipper and sharpened to maintain the clipper device cutting performance. Such blades may be attached to the clipper head by screws and the like or may have clips, clamps or other retention means for attachment to the clipper.
More modernly clippers have incorporated heads which are designed to include replaceable blades which blades are not intended to be continually sharpened, but rather to be removed and disposed. U.S. Pat. No. 2,722,742, issued Nov. 8, 1955 is an example of such a device. Also, clipper head assemblies which are disposable have been designed for use with clippers. An example of a plastic disposable head assembly for clippers is disclosed in U.S. Pat. No. 4,563,814, issued Jan.14, 1986.
The present invention provides an improved structure for a clipper head assembly with disposable blades. The entire assembly is such that the head assembly with blades is of the disposable type, but uses metal blades. If desired, the blades alone may be disposed and the head assembly reused; however, the structure is not intended for long wear and use. The head and blades are constructed such that the common problems encountered with existing removable/disposable heads and blades as for example heat retention in the blades and head and the catching and pulling of hair are minimized.
The support front edge of the base member of the present invention has no structure, such as comb teeth, which are under any portion of the cutting blades which comb teeth can catch and pull hair as, for example, in the U.S. Pat. No. 4,328,616, issued May 11, 1982 which has comb teeth under the cutting blade teeth such that when the two tooth elements are not in contact hair will be caught and pulled. In addition both cutting blades of the instant invention have a slightly concave shape, one relative to the other, along the entire blade longitudinal dimension to counter the tendency for blades to curl and separate which could cause the catching and pulling of hair as well as other problems. U.S. Pat. No. 4,765,060, issued Aug. 23, 1988 discloses a bend in the blade ends which may cause problems of separation as a result of a lack of a continuous concave shape along the longitudinal axis.
The cutting blades of the instant invention have indentations in the teeth to minimize heat build up and provide structural strength for the teeth. This is accomplished without the need for cut outs in the tooth edge wall which is done for example in sheep cutting clipper blades to provide flexibility. Such cut outs can cause loss of lubricants and also serve as a point that may catch and pull hair. In general, the new structure thus provides better cutting efficiency and minimum heat transfer to the subject being trimmed. The a disposable system achieves improved performance in cutting efficiency and is constructed to be used with existing comb snap on devices.
One object of the present invention is an improved cutting head structure for clippers which lowers friction and improves heat dissipation of the combination cutting head and blades to allow for a disposable clipper cutting head assembly. Another object is to reduce warpage of the head and/or blades during use in cutting to minimize hair pulling caused by hair becoming caught between the cutting blades rather than being cleanly cut. A further object is a disposable head and blade design which may be used with existing clip on combs. Another object is adaption of the cutting head for use with spring lock comb elements. A still further object is an upper cutting blade shoe structure for reduced friction wear of a clipper drive lug, which is usually plastic material, to which the upper blade shoe is engaged during clipper reciprocal drive operation. Another object is shielding of the clipper cavity which receives the cutting head to reduce the amount of hair or fur entering therein during a cutting operation. Yet another object is incorporation of protrusions in the base member to accommodate a variety of size of clipper blade socket mounting apparatus.